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The example of THERMOPLASTICALLY PROCESSABLE POLYURETHANES BASED ON SUCCINIC ACID PROPIONATES
EXAMPELS
A) Raw Materials Used:
PE 225 B butanediol adipate with a molecular weight of Mn=2,200 g/mol (BayerMaterialScience AG)
MDI diphenylmethane-4,4′-diisocyanate (BayerMaterialScience AG)
BUT 1,4-butanediol (BASF AG) 1,3-Propanediol, biobased (DuPont Tate & Lyle)
Succinic acid(cas:110-15-6) biobased, acid number: 946 mg of KOH/g corresp. to Mn=118.6 g/mol (Bioamber)
B) Preparation of the Polyesters:
BSP 1100 succinic acid 1,3-propionate with a molecular weight of Mn=1,100 g/mol
BSP 2200 succinic acid 1,3-propionate with a molecular weight of Mn=2,200 g/mol
BSP 2900 succinic acid 1,3-propionate with a molecular weight of Mn=2,900 g/mol
BSP 1100
2,421 g (20.41 mol) of biobased succinic acid(cas:110-15-6) and 1,817 g (23.87 mol) of 1,3-propanediol were initially introduced at room temperature, while covering with a blanket of nitrogen, into a 6 litre 4-necked flask equipped with a heating mushroom, mechanical stirrer, internal thermometer, 40 cm packed column, column head, descending intensive condenser and membrane vacuum pump and were heated slowly to 200° C., while stirring, water of reaction being distilled of from a temperature of approx. 140° C. After approx. 6 h, the reaction stopped. 70 mg of tin(II) chloride dihydrate were added, the pressure was reduced to 200 mbar in the course of approx. 2 h and the reaction was continued under these conditions for a further 16 hours. To bring the reaction to completion, the vacuum was reduced to 16 mbar for a further 4 h, the mixture was cooled and the following data were determined:
Analysis of the polyester BSP 1100: Hydroxyl number: 104.1 mg of KOH/g; acid number: 0.22 mg of KOH/g; viscosity: 11,800 mPas (25° C.), 1,470 mPas (50° C.), 405 mPas (75° C.)
BMS 101099
The OH and acid numbers were determined as described in “Methoden der organischen Chemie (Houben-Weyl), Makromolekulare Stoffe, volume 14/2, p. 17, Georg Thieme Verlag, Stuttgart 1963.
The viscosities were determined with a Physica MCR 51 viscometer from Anton Paar, equipped with a CP-50-1 measuring cone, at shear rates of between 1 and 1,000/s.
BSP 2200 [b)] and BSP 2900 [c)] were prepared analogously to BSP 1100, the molar ratios of dicarboxylic acid to diol having been changed to establish the molecular weights of the polyester polyols.
b) BSP 2200
Weight of 1,3-propanediol: 3,776 g (49.7 mol)
Weight of succinic acid(cas:110-15-6): 5,437 g (45.8 mol)
Weight of tin(II) chloride dihydrate: 270 mg
Analysis of the polyester: Hydroxyl number: 51.4 mg of KOH/g; acid number: 0.4 mg of
KOH/g; viscosity: 1,660 mPas (75° C.)
c) BSP 2900
Weight of 1,3-propanediol: 3,743 g (49.25 mol)
Weight of succinic acid(cas:110-15-6): 5,493 g (46.32 mol)
Weight of tin(II) chloride dihydrate: 180 mg
Analysis of the polyester: Hydroxyl number: 38.9 mg of KOH/g; acid number: 0.9 mg of
KOH/g; viscosity: 3,210 mPas (75° C.)
C. Preparation of the TPUs
In each case one polyol was initially introduced according to Table 1 into a reaction vessel. After heating up to 180° C., part amount 1 of the 4,4′-diphenylmethane-diisocyanate (MDI) was added, while stirring, and the prepolymer reaction was brought to a conversion of greater than 90 mol %, based on the polyol, with the aid of 50 ppm, based on the amount of polyol, of the catalyst tin dioctoate.
When the reaction had ended, part amount 2 of the MDI was added, while stirring. The amount of chain lengthener butanediol [BUT] stated in Table 1 was then added, the NCO/OH ratio of the components being 1.00. After intensive thorough mixing, the TPU reaction mixture was poured out on to a metal sheet and conditioned at 120° C. for 30 minutes.
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